1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright (C) 2001-2003 Red Hat, Inc. 5 * 6 * Created by David Woodhouse <dwmw2@infradead.org> 7 * 8 * For licensing information, see the file 'LICENCE' in this directory. 9 * 10 * $Id: super.c,v 1.110 2005/11/07 11:14:42 gleixner Exp $ 11 * 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/slab.h> 17 #include <linux/init.h> 18 #include <linux/list.h> 19 #include <linux/fs.h> 20 #include <linux/err.h> 21 #include <linux/mount.h> 22 #include <linux/jffs2.h> 23 #include <linux/pagemap.h> 24 #include <linux/mtd/mtd.h> 25 #include <linux/ctype.h> 26 #include <linux/namei.h> 27 #include "compr.h" 28 #include "nodelist.h" 29 30 static void jffs2_put_super(struct super_block *); 31 32 static struct kmem_cache *jffs2_inode_cachep; 33 34 static struct inode *jffs2_alloc_inode(struct super_block *sb) 35 { 36 struct jffs2_inode_info *ei; 37 ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL); 38 if (!ei) 39 return NULL; 40 return &ei->vfs_inode; 41 } 42 43 static void jffs2_destroy_inode(struct inode *inode) 44 { 45 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); 46 } 47 48 static void jffs2_i_init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) 49 { 50 struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo; 51 52 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 53 SLAB_CTOR_CONSTRUCTOR) { 54 init_MUTEX(&ei->sem); 55 inode_init_once(&ei->vfs_inode); 56 } 57 } 58 59 static int jffs2_sync_fs(struct super_block *sb, int wait) 60 { 61 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 62 63 down(&c->alloc_sem); 64 jffs2_flush_wbuf_pad(c); 65 up(&c->alloc_sem); 66 return 0; 67 } 68 69 static struct super_operations jffs2_super_operations = 70 { 71 .alloc_inode = jffs2_alloc_inode, 72 .destroy_inode =jffs2_destroy_inode, 73 .read_inode = jffs2_read_inode, 74 .put_super = jffs2_put_super, 75 .write_super = jffs2_write_super, 76 .statfs = jffs2_statfs, 77 .remount_fs = jffs2_remount_fs, 78 .clear_inode = jffs2_clear_inode, 79 .dirty_inode = jffs2_dirty_inode, 80 .sync_fs = jffs2_sync_fs, 81 }; 82 83 static int jffs2_sb_compare(struct super_block *sb, void *data) 84 { 85 struct jffs2_sb_info *p = data; 86 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 87 88 /* The superblocks are considered to be equivalent if the underlying MTD 89 device is the same one */ 90 if (c->mtd == p->mtd) { 91 D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name)); 92 return 1; 93 } else { 94 D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n", 95 c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name)); 96 return 0; 97 } 98 } 99 100 static int jffs2_sb_set(struct super_block *sb, void *data) 101 { 102 struct jffs2_sb_info *p = data; 103 104 /* For persistence of NFS exports etc. we use the same s_dev 105 each time we mount the device, don't just use an anonymous 106 device */ 107 sb->s_fs_info = p; 108 p->os_priv = sb; 109 sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index); 110 111 return 0; 112 } 113 114 static int jffs2_get_sb_mtd(struct file_system_type *fs_type, 115 int flags, const char *dev_name, 116 void *data, struct mtd_info *mtd, 117 struct vfsmount *mnt) 118 { 119 struct super_block *sb; 120 struct jffs2_sb_info *c; 121 int ret; 122 123 c = kzalloc(sizeof(*c), GFP_KERNEL); 124 if (!c) 125 return -ENOMEM; 126 c->mtd = mtd; 127 128 sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c); 129 130 if (IS_ERR(sb)) 131 goto out_error; 132 133 if (sb->s_root) { 134 /* New mountpoint for JFFS2 which is already mounted */ 135 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n", 136 mtd->index, mtd->name)); 137 ret = simple_set_mnt(mnt, sb); 138 goto out_put; 139 } 140 141 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n", 142 mtd->index, mtd->name)); 143 144 /* Initialize JFFS2 superblock locks, the further initialization will be 145 * done later */ 146 init_MUTEX(&c->alloc_sem); 147 init_MUTEX(&c->erase_free_sem); 148 init_waitqueue_head(&c->erase_wait); 149 init_waitqueue_head(&c->inocache_wq); 150 spin_lock_init(&c->erase_completion_lock); 151 spin_lock_init(&c->inocache_lock); 152 153 sb->s_op = &jffs2_super_operations; 154 sb->s_flags = flags | MS_NOATIME; 155 sb->s_xattr = jffs2_xattr_handlers; 156 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 157 sb->s_flags |= MS_POSIXACL; 158 #endif 159 ret = jffs2_do_fill_super(sb, data, flags & MS_SILENT ? 1 : 0); 160 161 if (ret) { 162 /* Failure case... */ 163 up_write(&sb->s_umount); 164 deactivate_super(sb); 165 return ret; 166 } 167 168 sb->s_flags |= MS_ACTIVE; 169 return simple_set_mnt(mnt, sb); 170 171 out_error: 172 ret = PTR_ERR(sb); 173 out_put: 174 kfree(c); 175 put_mtd_device(mtd); 176 177 return ret; 178 } 179 180 static int jffs2_get_sb_mtdnr(struct file_system_type *fs_type, 181 int flags, const char *dev_name, 182 void *data, int mtdnr, 183 struct vfsmount *mnt) 184 { 185 struct mtd_info *mtd; 186 187 mtd = get_mtd_device(NULL, mtdnr); 188 if (IS_ERR(mtd)) { 189 D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr)); 190 return PTR_ERR(mtd); 191 } 192 193 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt); 194 } 195 196 static int jffs2_get_sb(struct file_system_type *fs_type, 197 int flags, const char *dev_name, 198 void *data, struct vfsmount *mnt) 199 { 200 int err; 201 struct nameidata nd; 202 int mtdnr; 203 204 if (!dev_name) 205 return -EINVAL; 206 207 D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name)); 208 209 /* The preferred way of mounting in future; especially when 210 CONFIG_BLK_DEV is implemented - we specify the underlying 211 MTD device by number or by name, so that we don't require 212 block device support to be present in the kernel. */ 213 214 /* FIXME: How to do the root fs this way? */ 215 216 if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') { 217 /* Probably mounting without the blkdev crap */ 218 if (dev_name[3] == ':') { 219 struct mtd_info *mtd; 220 221 /* Mount by MTD device name */ 222 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4)); 223 for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) { 224 mtd = get_mtd_device(NULL, mtdnr); 225 if (!IS_ERR(mtd)) { 226 if (!strcmp(mtd->name, dev_name+4)) 227 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt); 228 put_mtd_device(mtd); 229 } 230 } 231 printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4); 232 } else if (isdigit(dev_name[3])) { 233 /* Mount by MTD device number name */ 234 char *endptr; 235 236 mtdnr = simple_strtoul(dev_name+3, &endptr, 0); 237 if (!*endptr) { 238 /* It was a valid number */ 239 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr)); 240 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt); 241 } 242 } 243 } 244 245 /* Try the old way - the hack where we allowed users to mount 246 /dev/mtdblock$(n) but didn't actually _use_ the blkdev */ 247 248 err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd); 249 250 D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n", 251 err, nd.dentry->d_inode)); 252 253 if (err) 254 return err; 255 256 err = -EINVAL; 257 258 if (!S_ISBLK(nd.dentry->d_inode->i_mode)) 259 goto out; 260 261 if (nd.mnt->mnt_flags & MNT_NODEV) { 262 err = -EACCES; 263 goto out; 264 } 265 266 if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) { 267 if (!(flags & MS_SILENT)) 268 printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n", 269 dev_name); 270 goto out; 271 } 272 273 mtdnr = iminor(nd.dentry->d_inode); 274 path_release(&nd); 275 276 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt); 277 278 out: 279 path_release(&nd); 280 return err; 281 } 282 283 static void jffs2_put_super (struct super_block *sb) 284 { 285 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 286 287 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 288 289 down(&c->alloc_sem); 290 jffs2_flush_wbuf_pad(c); 291 up(&c->alloc_sem); 292 293 jffs2_sum_exit(c); 294 295 jffs2_free_ino_caches(c); 296 jffs2_free_raw_node_refs(c); 297 if (jffs2_blocks_use_vmalloc(c)) 298 vfree(c->blocks); 299 else 300 kfree(c->blocks); 301 jffs2_flash_cleanup(c); 302 kfree(c->inocache_list); 303 jffs2_clear_xattr_subsystem(c); 304 if (c->mtd->sync) 305 c->mtd->sync(c->mtd); 306 307 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 308 } 309 310 static void jffs2_kill_sb(struct super_block *sb) 311 { 312 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 313 if (!(sb->s_flags & MS_RDONLY)) 314 jffs2_stop_garbage_collect_thread(c); 315 generic_shutdown_super(sb); 316 put_mtd_device(c->mtd); 317 kfree(c); 318 } 319 320 static struct file_system_type jffs2_fs_type = { 321 .owner = THIS_MODULE, 322 .name = "jffs2", 323 .get_sb = jffs2_get_sb, 324 .kill_sb = jffs2_kill_sb, 325 }; 326 327 static int __init init_jffs2_fs(void) 328 { 329 int ret; 330 331 /* Paranoia checks for on-medium structures. If we ask GCC 332 to pack them with __attribute__((packed)) then it _also_ 333 assumes that they're not aligned -- so it emits crappy 334 code on some architectures. Ideally we want an attribute 335 which means just 'no padding', without the alignment 336 thing. But GCC doesn't have that -- we have to just 337 hope the structs are the right sizes, instead. */ 338 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 339 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 340 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 341 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 342 343 printk(KERN_INFO "JFFS2 version 2.2." 344 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 345 " (NAND)" 346 #endif 347 #ifdef CONFIG_JFFS2_SUMMARY 348 " (SUMMARY) " 349 #endif 350 " (C) 2001-2006 Red Hat, Inc.\n"); 351 352 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 353 sizeof(struct jffs2_inode_info), 354 0, (SLAB_RECLAIM_ACCOUNT| 355 SLAB_MEM_SPREAD), 356 jffs2_i_init_once, NULL); 357 if (!jffs2_inode_cachep) { 358 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 359 return -ENOMEM; 360 } 361 ret = jffs2_compressors_init(); 362 if (ret) { 363 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 364 goto out; 365 } 366 ret = jffs2_create_slab_caches(); 367 if (ret) { 368 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 369 goto out_compressors; 370 } 371 ret = register_filesystem(&jffs2_fs_type); 372 if (ret) { 373 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 374 goto out_slab; 375 } 376 return 0; 377 378 out_slab: 379 jffs2_destroy_slab_caches(); 380 out_compressors: 381 jffs2_compressors_exit(); 382 out: 383 kmem_cache_destroy(jffs2_inode_cachep); 384 return ret; 385 } 386 387 static void __exit exit_jffs2_fs(void) 388 { 389 unregister_filesystem(&jffs2_fs_type); 390 jffs2_destroy_slab_caches(); 391 jffs2_compressors_exit(); 392 kmem_cache_destroy(jffs2_inode_cachep); 393 } 394 395 module_init(init_jffs2_fs); 396 module_exit(exit_jffs2_fs); 397 398 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 399 MODULE_AUTHOR("Red Hat, Inc."); 400 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 401 // the sake of this tag. It's Free Software. 402